Dynamics of neuroepithelial cell proliferation in the developing chick optic tectum.

RAPACIOLI M; ORTALLI A; RODRÍGUEZ-LIMARDO R; SÁNCHEZ V; SCICOLONE G; FLORES V

Cancun

Congreso; First Pan American Congress in Developmental Biology; 2007

Sociedad Latinoamericana de Biologia del Desarrollo.

First Pan American Congress in Developmental Biology. Society for Developmental Biology Latinamerican Society for Developmental Biology Cancun, Mexico June 16–20, 2007 Dynamics of neuroepithelial cell proliferation in the developing chick optic tectum. Rapacioli M, Ortalli A, Rodríguez-Limardo R, Sánchez V, Scicolone G, Flores V. Best Student Poster Competition Honorable Mention The developing chick optic tectum is used as experimental model to analyze spatial/temporal organization of proliferative activity. Analyses of variability of proliferation were performed as a function of cephalic-caudal and dorsal-ventral axes during the entire proliferative period. Spatial coordinates of every mitotic cell were recorded on histological complete sections. Several space signals representative of the proliferative process were constructed in order to apply conventional statistical methods (ANOVA test and Kruskall-Wallis), spectral analysis (Power Spectral Density) and non-linear methods (Fano Factor, Allan Factor, Detrended Fluctuation Analysis) that allow dynamics characterization and scaling coefficient estimation. Results indicate that a) the proliferation dynamics significantly changes as a function of the developmental stage; b) it is comprised by deterministic and stochastic components; c) the deterministic component can be described as a global trend; d) the second one corresponds to a stochastic process whose values of scaling coefficients are indicative of the existence of local correlation. These results can be interpreted as manifestation of the operation of a) a long-range developmental influence that installs space-dependent differences on the whole neuroepithelial cell population along the cephalic-caudal axis and b) short-range interactions among proliferating cells leading to clusterization and a non-uniform spatial distribution. These theoretical analyses interpreted together with 2D and 3D reconstructions and proliferative activity representations indicate that there exists a defined area of the tectal hemisphere (“proliferation region”) of maximal activity that characteristically moves towards the caudal end as development progresses. Supported by grants from CONICET and UBACYT (Argentina)